The most dangerous of devotions, in my opinion, is the one endemic to Christianity: I was not born to be of this world. With a second life waiting, suffering can be endured - especially in other people. The natural environment can be used up. Enemies of the faith can be savaged and suicidal martyrdom praised.

In the end ... success or failure will come down to an ethical decision, one on which those now living will be judged for generations to come.

The closer the genetic relationship of the family members, as for example father-to-son, as opposed to uncle-to-nephew, the higher the degree of cooperation.

Human nature is deeper and broader than the artificial contrivance of any existing culture.

We don't need to clear the 4 to 6 percent of the Earth's surface remaining in tropical rain forests, with most of the animal and plant species living there.

Individual versus group selection results in a mix of altruism and selfishness, of virtue and sin, among the members of a society. If one colony member devotes its life to service over marriage, the individual is of benefit to the society, even though it does not have personal offspring. A soldier going into battle will benefit his country, but he runs a higher risk of death than one who does not. An altruist benefits the group, but a layabout or coward who saves his own energy and reduces his bodily risk passes the resulting social cost to others.

Adults forget the depths of languor into which the adolescent mind decends with ease. They are prone to undervalue the mental growth that occurs during daydreaming and aimless wandering